I have a PS3, and for me its a glorified Blu-Ray, DVD, and DivX player. I can't remember the last time I played a game on it, and in fact I regret buying the few that I have (other than Guitar Hero, which I'd keep, even if I haven't played it in a long long time). I do think the PS3 is worth it just as a Blu-Ray player though. I in no way regret buying the system (as opposed to the games).
If you're a fairly serious console gamer, the 360 is the way to go. I'm not but I know a lot of people who are. Everyone I know that has a Wii says that it gets old real fast (except for GH as previously stated).
As for Windows 7... like Vista I'm in wait-and-see mode. Having skipped Vista entirely I'm probably more likely to give Windows 7 a chance. But not if my ability to run my favorite apps is gone or diminished.